The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2001-305564 and 2001-305362 both filed on Oct. 1, 2001 the entire contents thereof is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a liquid-operated steering damper suitable for a saddle-type vehicle such as a motorcycle that is used to inhibit the run-out of a handlebar during operation.
2. Description of Background Art
As disclosed in Japanese published patent application No. 2593461, a liquid-operated steering damper that generates damping force for run-out to prevent the run-out of a handlebar by kickback and other disturbances is well-known. A liquid-operated steering damper the damping force generated by which is variable so that damping force is generated only when the force is required and no excessive damping force is generated in other cases is also well-known. For example, a liquid-operated steering damper that provides control based upon a steering angle and running speed is disclosed in Japanese published unexamined patent application No. Sho63-64888. In addition, a liquid-operated steering damper that provides control based upon the variation of a front wheel load is disclosed in Japanese published examined patent application Hei7-74023.
When a relatively heavy liquid-operated steering damper is supported by a steering portion such as a steering shaft, the inertia of steering increases. However, it is desirable that such inertia of steering should be reduced as much as possible. Since a main switch and various meters are arranged in the vicinity of the upper end of a steering shaft, it is desirable that a steering damper is arranged to provide operability for these elements. Thus, the forward visibility of a rider is impaired. The object of the invention is to overcome such problems.
To achieve the object, a steering damper for a saddle-type vehicle is provided wherein the upper end of a steering shaft is fitted to the inside of the steering damper and is interlocked with a turning member for generating damping force. The steering damper is fixed to the side of a body frame in a saddle-type vehicle on the front of the body frame wherein a head pipe is provided and the liquid-operated steering damper is coupled to the upper end of the steering shaft supported by the head pipe.
The present invention includes a part having a large diameter and a part having a small diameter that are provided on the upside of the steering shaft. The part having a small diameter is fitted to the inside of the steering damper.
The present invention includes a part having a small diameter of the steering shaft that protrudes upwardly from the steering damper and the steering damper and a top bridge arranged below the steering damper are fixed to the upside of the steering shaft by a fixing member attached to the protruding upper end by jointly fastening. The top bridge means, a part of a steering system, is a member for coupling the steering shaft and each upside of right and left front forks. A main switch is supported in the front of the top bridge.
According to the present invention, as the upper end of the steering shaft is fitted to the inside of the steering damper, is interlocked with a turning member for generating damping force and the relatively heavy steering damper is fixed to the side of the body frame, the steering shaft has only to be coupled to the turning member for generating damping force which is a relatively light part of the steering damper and the inertia of steering can be reduced though the steering damper is provided over the steering shaft.
According to the present invention, as the part having a large diameter and the part having a small diameter are provided to the upside of the steering shaft, the part having a small diameter is fitted to the inside of the steering damper and is interlocked with the turning member for generating a damping force, a part to be provided to the steering shaft to couple to the steering damper is only the part having a small diameter. Therefore, the steering shaft can be made relatively light.
According to the present invention, as the steering damper and the top bridge arranged below the steering damper are fixed to the steering shaft by the fixing member attached to the upper end of the part having a small diameter protruding upward through the steering damper by jointly fastening, a steering nut heretofore required and under the steering damper can be omitted. That is, heretofore, the top bridge is fastened to the upside of the steering shaft under the steering damper by the steering nut. However, the top bridge can be fixed by the steering damper. Therefore, a position in which the steering damper is attached can be lowered and the steering damper can be prevented from having an effect upon the operability of the main switch and the riding position and the forward visibility of a rider.
In case the steering damper utilizing hydraulic pressure as described above is arranged from the upside of a head pipe to the rear in a saddle-type vehicle in which a fuel tank is located at the back of the head pipe such as a motorcycle, the steering damper is required to be arranged so that the rear of the steering damper and the fuel tank do not interfere. At this time, in case a position in which the steering damper is attached is made high to avoid the fuel tank, the forward visibility of a rider may be influenced. In the meantime, when a position in which the steering damper is attached is lowered, the front of the fuel tank is required to be backed at the back of the rear end of the steering damper and as a result, the capacity of the fuel tank may be sacrificed. Then, it is desirable that a position in which the steering damper is attached can be lowered and the reduction in the capacity of the fuel tank can be minimized. The invention is made to realize such a result.
A steering damper for a saddle-type vehicle according to the present invention includes a steering damper that is arranged from the upside of a head pipe to the rear. The rear of the steering damper is housed in a concave portion provided at the front end of a fuel tank in a saddle-type vehicle in which the head pipe is arranged in the front of a body frame, the fuel tank is arranged at the back of the head pipe and the steering damper is provided between the body frame and a steering system.
The present invention according provides a steering damper that is a liquid-operated type configured to control a damping characteristic. A control valve for controlling the damping characteristic is provided to the rear of the steering damper housed in the concave portion.
According to the present invention, as the concave portion is provided at the front end of the fuel tank and the rear of the steering damper is housed in the concave portion, a position in which the steering damper is attached is possibly lowered, the satisfactory forward visibility of a rider can be secured and the reduction of the capacity of the fuel tank can be minimized.
According to the present invention, as the control valve is provided to the rear of the steering damper and is arranged in the concave portion of the fuel tank an external force is prevented from being applied to the control valve by the fuel tank and the control valve can be securely protected.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.